Rear shocks possible problem

First I will post a pic when I get home later. I noticed my driver side shock between the top nut and washer then the bushing has a gap about .25". Tried searching for the cause and found nothing so far. Then this morning I though shit I hope I don't have a brOken leaf. Should have my new shocks today but looking for some helOm here before I install them. Also, anyone know why there are two different part numbers for the rear shocks. I didnt go with OEM I got the billstien. I have notice sin e I bought the truck 13K miles ago the popping sound from the rear figured it was something from the bed but sound is getting worse and the shocks were said to be rePlaced by the dealer back then ne'er were and it was to late before I saw the service history on Toyota shame on me. The truck is still a great truck.
Thanks

 

On my 04 D-cab, the rear shocks had two different numbers also. It is because they are different lengths. If I remember correctly, the passenger side is slightly shorter than the driver's side.

 

I saw that somewhere here before I think but I couldn't remeber for what generation I have a 2nd Gen. Here is a pic of my problem has anyone seen this before.

 

My guess would be that the other bushing on the underside of the bracket is wore out. You will have to take it off to see what the issue is.

 

+1 on this too. It's hard telling. The best thing would be to remove the shock. Until then, you won't know.

As for tightening it down, it looks like the nut is as far down as it can go. I don't see any threads below the nut, which means it's already down to the smooth part of the stud.

 

Tried to tighten it and I stuck my fingers up under the mount and felt the washer and bushing. One thing I noticed on the back of the shock the paint is scratched off and for only being replaced at 49k miles like the dealer says they did I still hink they are the OEM. I guess this is not usually something seen. I went and bought 5100's hope fully I will be changing this weekend, and take a better look at them. Just one more drive to work dealing with the odd piping sound it makes. And checked the other shock that is loose too, no gap but I can wobble it like some thing is not tight. When I tried to make sure they were tight the little tit on top of the threads snapped off easily. Now I get to cut the top off

All the above replys would be the dealership screwed up like they tried to screw me on my alignment.